I have browsed the hypbrid forum's search results on 'battery' and found lots of useful information, though some of it seems contradictory (or just confusing to me). I have decided to start a new thread with a summary of what I think I have learned. Hopefully some of you experts out there will verify and/or correct this note.
Background:
Like many others, I have had problems with the 12V battery in the 400h. Like a few others, my first time was the day I left the dealer. Sitting in the car in my driveway, enjoying playing with the wealth of niftyfeatures on the dashboard, plus the power moonroof and probaby the power rear door, suddenly the dash lights blinked and went dark, and I ended up unable to start the car! Normally, I figure if the interior lights are bright, and the horn honks, and for this model, the steering wheel extends when I insert the key, the battery must be okay. Not true! Even the dash lights would come back on when I reintroduced the key, but turning the key to START would not light the READY light, and hence, NO GO! (Happily, the dealer sent out a technician who jump started the car.)
After reading many threads in these informaiton rich forums, my understanding is that the traction battery recharges the 12v battery, rather than an alternator powered by the gas engine. Does this only happen when the key is inserted? Does this only happen in certain key positions?
The technician who came out to jump start the car told me that the gas engine charges the 12v. He also told me that the 12v starts the gas engine as well as handles all the usual 12v features of regular, non-hybrid cars. This seemed rather odd to me - sort of a Catch 22, at least for a hybrid where there is a wealth of charged up electrical power. However the fact that he jump started the car with a 12v jumper battery connected to the 12v 400h battery gave me reason to believe him.
So, is my learning correct (see bold text above)? Or is the technician right? Or is it something in between???
Even if I have learned correctly from these forum threads, I remain baffled by a system that can have plenty of traction battery power to drive the car but still have insufficient 12v power to turn on the READY light so I can actually drive it. The role that the 12v battery plays in this seems misplaced, but maybe that is just my engineering mind working overtime...
Perhaps if I had left the car overnight, in the morning the slow charging of the 12v from the traction battery would allow me to drive my 400h again without a jump?
Thanks in advance for any clarity and advise!
